Ship Expansion Joints: Types and Applications Explained

Expansion joints are often called movement joints. Related terms include control joints, which manage cracking in concrete, and isolation joints, which separate different parts of a structure, like a slab from a column. While the terms vary based on function, all create a gap that requires a flexible sealant, which WEATHERCAP® is designed to protect.

WEATHERCAP® is made of soft lead. This material is chosen for its unique properties: it is extremely flexible, durable, and has a low elastic modulus. This allows it to 'creep' and adapt to new joint configurations as a building settles or moves over time, ensuring a continuous, permanent, and weather-resistant seal without retaining a rigid shape that could fail.

Absolutely. While it is renowned for historic preservation, WEATHERCAP® is highly effective for new construction projects. Installing it from the outset provides superior, long-term protection for masonry joints, extending the life of the sealant and preventing costly moisture-related issues down the line. The A-2 model is specifically intended for new construction.

Type A is a flat cap designed for joints where masonry units are in the same plane, such as the top joints of a stone coping or a balustrade. Type B is a 90-degree cove cap used for right-angle joints, like where a projecting window lintel or cornice meets a vertical wall. This ensures a proper fit and seal for different architectural geometries.

It acts as a durable, physical shield over the sealant. This covering protects the sealant from direct exposure to UV radiation, rain, ice, and physical abrasion, which are the primary causes of sealant degradation and failure (margin checking). By protecting the sealant, WEATHERCAP® dramatically extends its functional service life and prevents leaks.

WEATHERCAP® is designed for professional installation by experienced masonry contractors. The soft lead cap is interposed within a sealant-filled joint. To ensure proper application for a lasting seal, we provide comprehensive manufacturer support, including technical information, sample specifications, CAD drawings, and detailed installation guidance.